How to use collections.abc from both Python 3.8+ and Python 2.7 [duplicate]

This question already has an answer here:

Python 2 and Python 3 dual development

6 answers

In Python 3.3 "abstract base classes" in collections (like MutableMapping or MutableSequence) were moved to second-level module collections.abc. So in Python 3.3+ the real type is collections.abc.MutableMapping and so on. Documentation states that the old alias names (e.g. collections.MutableMapping) will be available up to Python 3.7 (currently the latest version), however in 3.8 these aliases will be removed.

Current version of Python 3.7 even produces a warning when you use the alias names:

./scripts/generateBoard.py:145: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working

  elif isinstance(value, (collections.MutableMapping, collections.MutableSequence)) == True:

In python 2.7 there is no collections.abc.

How can Python script handle this difference in the most convenient way, when it is meant to be used with (almost) any Python version? I'm looking for a solution which would ideally solve this mess in one central place, without having to use try: ... except: ... all over the script everywhere I need this type?

edited Dec 30 '18 at 16:18

JJJ

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asked Dec 30 '18 at 14:42

Freddie Chopin

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marked as duplicate by jonrsharpe python
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Dec 30 '18 at 14:57

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment |

This question already has an answer here:

Python 2 and Python 3 dual development

6 answers

Current version of Python 3.7 even produces a warning when you use the alias names:

./scripts/generateBoard.py:145: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working

  elif isinstance(value, (collections.MutableMapping, collections.MutableSequence)) == True:

In python 2.7 there is no collections.abc.

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

marked as duplicate by jonrsharpe python
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Dec 30 '18 at 14:57

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment |

This question already has an answer here:

Python 2 and Python 3 dual development

6 answers

Current version of Python 3.7 even produces a warning when you use the alias names:

./scripts/generateBoard.py:145: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working

  elif isinstance(value, (collections.MutableMapping, collections.MutableSequence)) == True:

In python 2.7 there is no collections.abc.

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

This question already has an answer here:

Python 2 and Python 3 dual development

6 answers

Current version of Python 3.7 even produces a warning when you use the alias names:

./scripts/generateBoard.py:145: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working

  elif isinstance(value, (collections.MutableMapping, collections.MutableSequence)) == True:

In python 2.7 there is no collections.abc.

This question already has an answer here:

Python 2 and Python 3 dual development

6 answers

python python-3.x python-2.7

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

edited Dec 30 '18 at 16:18

JJJ

29.1k147591

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

asked Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

marked as duplicate by jonrsharpe python
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Dec 30 '18 at 14:57

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Dec 30 '18 at 14:57

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1 Answer
1

active

oldest

votes

Place this at the top of the script:

import collections



try:

    collectionsAbc = collections.abc

except AttributeError:

    collectionsAbc = collections

Then change all prefixes of the abstract base types, e.g. change collections.abc.MutableMapping or collections.MutableMapping to collectionsAbc.MutableMapping.

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

add a comment |

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

Place this at the top of the script:

import collections



try:

    collectionsAbc = collections.abc

except AttributeError:

    collectionsAbc = collections

Then change all prefixes of the abstract base types, e.g. change collections.abc.MutableMapping or collections.MutableMapping to collectionsAbc.MutableMapping.

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

add a comment |

Place this at the top of the script:

import collections



try:

    collectionsAbc = collections.abc

except AttributeError:

    collectionsAbc = collections

Then change all prefixes of the abstract base types, e.g. change collections.abc.MutableMapping or collections.MutableMapping to collectionsAbc.MutableMapping.

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

add a comment |

Place this at the top of the script:

import collections



try:

    collectionsAbc = collections.abc

except AttributeError:

    collectionsAbc = collections

Then change all prefixes of the abstract base types, e.g. change collections.abc.MutableMapping or collections.MutableMapping to collectionsAbc.MutableMapping.

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

Place this at the top of the script:

import collections



try:

    collectionsAbc = collections.abc

except AttributeError:

    collectionsAbc = collections

Then change all prefixes of the abstract base types, e.g. change collections.abc.MutableMapping or collections.MutableMapping to collectionsAbc.MutableMapping.

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

answered Dec 30 '18 at 14:42

Freddie Chopin

4,7451439

add a comment |

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